Max DC current flow on 12V_OUT on 8-pin VTO3221E-P connector

[dimpap]

Friends, need your help please. I can't find any information about rated current on this pin anywhere in the documentation.
I want to supply the electromagnetic latch from the 12V_OUT pin available on the 8-port connector at the VTO3221E-P intercom. The intercom itself is powered through POE. The manufacturer did not indicate in the datasheet on the VTO3221E-P the rated current that this output can be loaded with, it just says 12V_out, and that's it. I remember that the maximum current on a standard latch is about 280mA at 12V DC, and it should stay powered for up to 10 seconds approximately. Does anyone know what is the rated output current on this 8-pin connector ?
And yes, I know that I c

 

[CanCuba]

Excellent question and I'm curious myself as I'm working towards finally setting up the same type of 12v electric lock for my front gate.

Another option is to use a POE splitter if you're using POE to power it:

https://a.co/d/5UQlxSe

From there, you would use a DC barrel y-cable to split the 12v DC for the VTO and for the electric lock. This will give you more than enough power to fire the solonoid on the electric lock. I think the specs on mine say 1 amp (12w) peak draw when the solonoid activates.

Personally, I'd go with the POE splitter as this eliminates the chance of the electric lock burning out the VTO due to overdraw.

 

[TonyR]

+1^^.
All images of connectors depict any external locks and latches being powered by an external power supply and connected to the 12 pin connector, not the 8.
The 8 pin is for data devices such as RS-485 devices or a Wiegand card reader, which I beilieve uses 5 VDC.

As you probably know, electro-magnetic latches and strikes can have high currents as the field to the magnetic coil collapses and produce back EMF which can damage solid state outputs (not a "dry" relay output).

 

[dimpap]

Another option is to use a POE splitter if you're using POE to power it:

Yes, thank you ! Definately a good solution ! I thought about it too, but worried about rated power of this splitter, which could be too low for the VTO. Dahua's datasheet indicates 12V 2A PSU to be used with this VTO (and in addition we need another 300mA for the lock). I thought about using splitter you proposed with sort of POE doubler ogy.de/4dlz - maybe that could help while the VTO will stay connected to the second POE outlet, and latch will receive power from the splitter you proposed, staying connected to the first POW outlet. The truth is that the installation place in my case is a bit tight for the doubler + splitter + connections between them .... But sims I have no too much options, since danger of back EMF which TonyR mentioned is real. I do not beleive manufacturer cared about any protection while clearly declared this port is for 485 devices only.

produce back EMF which can damage solid state outputs

You're 100% right, thank you for this remark !

 

[CanCuba]

Yes, thank you ! Definately a good solution ! I thought about it too, but worried about rated power of this splitter, which could be too low for the VTO. Dahua's datasheet indicates 12V 2A PSU to be used with this VTO (and in addition we need another 300mA for the lock). I thought about using splitter you proposed with sort of POE doubler ogy.de/4dlz - maybe that could help while the VTO will stay connected to the second POE outlet, and latch will receive power from the splitter you proposed, staying connected to the first POW outlet. The truth is that the installation place in my case is a bit tight for the doubler + splitter + connections between them .... But sims I have no too much options, since danger of back EMF which TonyR mentioned is real. I do not beleive manufacturer cared about any protection while clearly declared this port is for 485 devices only.



You're 100% right, thank you for this remark !

I just checked the POE output page on my NVR. VTO idle is drawing 2.7w (while it's being recorded to the NVR) and 3.2w during a call (call initiated from the VTH) so that's just a fraction of the 24w (12v @ 2A) listed.

The 2A I'm sure if for the VTO itself plus any accessories added to it. Autotracking PTZs draw close to 24w and the VTO is nowhere near the computing power of a PTZ nor is it driving any motors.

The splitter you listed draws 3 watts (I run a couple of these things) before powering the cameras so that will be drawing power away from the POE before it powers any cameras. If your NVR/switch isn't POE+ (25.5w output), you could use a POE injector to get it to 802.3at (POE+) power.

But if the VTO is drawing 3.2 watts during a call and the electric lock/strike would draw 1 amp (12 watts @ 12 volts), you're still well-within the 18 watt max of the POE splitter I linked.

There are higher output POE splitters like this one but I really don't think it's necessary.

You would need a DC barrel splitter and DC barrel connectors to make the connections but that's a minor detail.

 

[dimpap]

Thank you so much for this very valuable information you shared. I'm going to try with the the splitter. Will search it in my location now and will share the result

 

[CanCuba]

Thank you so much for this very valuable information you shared. I'm going to try with the the splitter. Will search it in my location now and will share the result

This is exactly what the forum is for. I'm far, far from the most knowledgeable member but I like to help where I think I can.

The splitters are great little devices. I have my NVR hooked up to a 150ah gel battery array so I take advantage of it and run my access point off the 12v provided by a splitter. Not needing a separate wire for powering the access point keeps my wife happy. Or at least happier! lol